Hypoglycemic prodrugs of 4-(2,2-dimethyl-1-oxopropyl)benzoic acid

Iron-Catalyzed Regio- and Stereoselective C-H Alkenylation of Pivalophenone Derivatives with Unsymmetric Internal Alkynes

Here we report an ortho-C-H alkenylation of aromatic ketones with unsymmetric internal alkynes catalyzed by an iron phosphine complex, Fe(PMe₃)₄. The use of a catalytic amount of P^tBu₃ as an additive was found to improve the product yields. The alkenylation proceeds regio- and stereoselectively to give the corresponding styrene derivatives.

Design, synthesis and antifungal activity of (E)-3-acyl-5-(methoxyimino)-1,5-dihydrobenzo[e][1,2]oxazepin-4(3H)-one analogues

Nitrogen- or oxygen-containing organic compounds which have significant antifungal activity, twenty one novel nitrogen or oxygen-containing (E)-3-acyl-5-(methoxyimino)-1,5-dihydrobenzo[e][1,2]oxazepin-4(3H)-one analogues were designed and synthesized, and their structures were confirmed by ¹H NMR, ¹³C NMR and HRMS. Preliminary bioassay showed that most of them exhibited certain-to-good antifungal activity. Compounds 5k-2, 5n, 5p and 5r exhibited over 80% inhibitory rate against Sclerotinia sclerotiorum at 50 μg/mL, and 5r exhibited good antifungal activity against S. sclerotiorum with EC₅₀ of 7.21 μg/mL. Compounds 5a and 5r also showed over 90% inhibition against Botrytis cinerea. In particular, 5r showed significant higher activity with the lowest EC₅₀ of 7.92 μg/mL than the positive control trifloxystrobin (21.96 μg/mL) and azoxystrobin (9.43 μg/mL). Providing a practical method for the synthesis of new scaffolds 1,2-Benzoxazepinone and systematically investigate their antifungal activity.

Mitochondria: new drug targets for oxidative stress-induced diseases

The identification of the mitochondrion as the gatekeeper of the life and death of a cell and the appreciation of the role of mitochondrial dysfunction in a range of clinical disease processes have made the mitochondrion a target for drug delivery. Accordingly, strategies are being developed for the targeted delivery of antioxidants to mitochondria. Recent studies show that triphenylphosphonium-based antioxidants and amino acid- and peptide-based antioxidants protect mitochondria against oxidative insult. Future studies will undoubtedly exploit the unique biophysical and biochemical properties of mitochondria, including mitochondrial activation of prodrugs, for the targeted delivery of cytoprotective agents.

N-hydroxybenzenecarboximidic acid derivatives: a new class of nitroxyl-generating prodrugs

On the basis of the propensity of Piloty's acid to generate nitroxyl (HNO), we previously prepared a number of N,O-bisacylated Piloty's acid derivatives and showed that such prodrugs underwent a disproportionation reaction following ester hydrolysis to give an unstable intermediate that hydrolyzed to nitroxyl. To expand the versatility of this series, we desired some mixed N,O-diacylated Piloty's acid derivatives and devised a synthetic route to them. Such efforts led us, serendipitously, to a new series of heretofore unreported nitroxyl-generating compounds. Thus, benzohydroxamic acid was acylated on the hydroxylamino oxygen and the resulting product converted to its sodium salt. Treatment of this salt with arenesulfonyl chorides would be expected to give the mixed N,O-diacylated derivatives of Piloty's acid. However, the products obtained were the isomeric carboximidic acid derivatives whose structures were deduced from the IR and (13)C NMR spectral frequencies associated with the sp(2) carbons. The structures were verified by analysis of the X-ray crystal structure of a prototype compound of this series. When incubated with porcine liver esterase or mouse plasma, these N-acyloxy-O-arenesulfonylated benzenecarboximidic acid derivatives liberated HNO, measured as N(2)O, as well as the expected arenesulfinic acid and benzoic acid. Alkaline hydrolysis also produced N(2)O, but the major products were the arenesulfonic acid and benzohydroxamic acid. Thus, these N-hydroxybenzenecarboximidic acid derivatives represent a new series of nitroxyl prodrugs that require enzymatic bioactivation before nitroxyl can be liberated.